이원종 Won-jong Lee , 윤소정 Soh-joung Yoon , 전철민 Chul-min Chon , 허철호 Chul-ho Heo , 이길재 Gill-jae Lee , 이범한 Bum-han Lee , Murat Cicek

DOI: Vol.29(No.4) 167-177, 2016

Smectitic clays, occurring in Kırka and Bigadic boron evaporite deposits formed in Miocene playa lake environment in Turkey, contain LiO₂ 0.02-0.21% and 0.16-0.30%, respectively, and boron tailings are also reported to contain LiO₂ 0.04-0.26%. Lithium in smectitic clays was identified to be retained in hectorite. The XRD results revealed that hectorite was contained in 25.7% and 79.7% of Kırka and Bigadic deposit samples respectively. In this study, we selected a clay sample from each deposit with lithium content of ~0.18% and estimated extractable lithium by acid treatment and roasting method commercially applicable to lithium resources, such as lepidolite and hectorite. When 1 g of crushed clay (particle size less than 74 μm) was reacted with 200 mL of 0.25 M HCl solution, the amount of lithium dissolved increased with the increase of reaction time up to 10 hours for both samples. Reaction time longer than 10 hours did not significantly increased the amount of lithium dissolved. After 10 hours of reaction, 89% of lithium in the clay sample from the Kırka deposit was dissolved, while 71% of lithium was dissolved from the Bigadic deposit tailing sample. 87% of lithium in the clay sample from the Kırka deposit was extracted and 82% of lithium was extracted from the Bigadic deposit tailing sample by the roasting extraction method, where clays were leached after a thermal treatment at 1,100℃ for 2 hours with CaCO₃ and CaSO₄.

산 처리, 비가디치광상, 크르카광상, 헥토라이트, 붕소, 리튬추출, Acid treatment, roasting method, Kirka, Bigadic, hectorite, Li-extraction

문동혁 Dong Hyeok Moon , 한민수 Min Su Han , 조현구 Hyen Goo Cho , 김명남 Myoung Nam Kim , 김재환 Jae Hwan Kim

DOI: Vol.29(No.4) 179-190, 2016

X-ray diffraction analysis, chromaticity measurement, execution and evaluation by Dancheong artisan, accelerated weathering test, and fire resistance test were conducted to test the applicability as a Dancheong pigment raw materials of Korean low grade kaolin in cultural properties. The ores that feldspar rich and composed of fine particles (＜ 38.1 μm) showing advantageous for the inherent purpose of the white pigment than that of high grade kaolin. And the test of whiteness, concealment force, outdoor exposure durability and fire resistance shows similar or better result than existing products (Hobun and Sanhwa jidang). In conclusion, it is expected that the use of fine feldspar rich white soil and low-grade kaolin can be used as a white pigment raw materials which have similar to better material properties and economic efficiency than existing products.

고령토, 저품위 고령토, 장석질 백토, 단청안료, 대체원료, kaolin, low grade kaolin, feldspar rich white soil, Dancheong pigment, raw material for replacement

김영호 Young-ho Kim , 이누리 Nuri Lee

DOI: Vol.29(No.4) 191-198, 2016

Pyromorphite(Pb_4.85(P_1.02O₄)₃Cl_1.04) which belongs to the apatite group was compressed up to 33.4 GPa for its equation of state at ambient temperature. High pressure experiment was performed with symmetrical diamond anvil cell employing the angle dispersive X-ray diffraction method. Pressure was determined by ruby fluorescence calibration method. No phase transition were observed and bulk modulus was determined to be 80(7) GPa when K₀` = 13(2). Employing the normalized pressure-normalized strain analysis, reliability check of the compressible behavior was conducted.

녹연석, 상태방정식, 체적탄성률, 정규화압력, 정규화응력변형, pyromorphite, equation of state, bulk modulus, normalized pressure, normalized strain

우엄식 Eum Sik Woo , 김영훈 Young Hun Kim , 김정진 Jeong Jin Kim

DOI: Vol.29(No.4) 199-207, 2016

One of the most significant environmental issues in abandoned coal mine is acidic drainage which gives rise to the many environmental problems that acidifying streams water, sedimentation of iron/aluminium hydroxide, and pollution of water and soil. Water and precipitate samples for experiments were collected from stream and bottom in the pit mouth of Sambong mine. Mine water shows pH range from 7.24 to 7.94 in winter and 3.87 to 5.73 in summer season. The EC shows range from 432 to 897 μS/cm at the stream receiving mine water. The highest concentrations of cations such as Mg, Al, Ca, and Mn are showing 15.50, 4.56, 85.30, 12.76 mg/L in the pit mouth, respectively. The reddish brown precipitates (Munsell color 10R-5YR in winter and 2.5YR-5Y in summer) consist mainly of 2-line ferrihydrite and schwertmannite. The precipitates are characterized by rod or cylindrical forms, and coccus or sphere of 0.1 to 0.5 μm in diameter.

폐석탄광산, 산성광산배수, 페리하이드라이트, 슈워트마나이트, 침전물, abandoned coal mines, acid mine drainage, ferrihydrite, schwertmannite, precipitates

손상보 Sangbo Son , 권기덕 Kideok D. Kwon

DOI: Vol.29(No.4) 209-220, 2016

Clay minerals are a major player to determine geochemical cycles of trace metals and carbon in the critical zone which covers the atmosphere down to groundwater aquifers. Molecular dynamics (MD) simulations can examine the Earth materials at an atomic level and, therefore, provide detailed fundamental-level insights related to physicochemical properties of clay minerals. In the current study, we have applied classical MD simulations with clayFF force field to dioctahedral clay minerals (i.e., gibbsite, kaolinite, and pyrophyllite) to analyze and compare structural parameters (lattice parameter, atomic pair distance) with experiments. We further calculated vibrational power spectra for the hydroxyls of the minerals by using the MD simulations results. The MD simulations predicted lattice parameters and interatomic distances respectively deviated less than 0.1~3.7% and 5% from the experimental results. The stretching vibrational wavenumber of the hydroxyl groups were calculated 200-300 cm^-1higher than experiment. However, the trends in the frequencies among different surface hydroxyl groups of each mineral was consistent with experimental results. The angle formed by the surface hydroxyl group with the (001) plane and hydrogen bond distances of the surface hydroxyls were consistent with experimental result trends. The inner hydroxyls, however, showed results somewhat deviated from reported data in the literature. These results indicate that molecular dynamics simulations with clayFF can be a useful method in elucidating the roles of surface hydroxyl groups in the adsorption of metal ions to clay minerals.

이팔면체 점토광물, 분자동역학 시뮬레이션, ClayFF, 파워스펙트럼, 수소결합, dioctahedral clay minerals, molecular dynamics simulations, surface hydroxyls, vibrational power spectra, hydrogen bond

박상희 Sanghee Park , 류종식 Jong-sik Ryu , 신형선 Hyung Seon Shin , 길영우 Youngwoo Kil , 조윤수 Yunsoo Jo

DOI: Vol.29(No.4) 221-227, 2016

Copper is an essential transition metal involving in various biogeochemical processes. With the recent advances in analytical techniques and mass spectrometry, such as MC-ICP-MS, it is possible to measure Cu isotopes, which allows us to understand various biogeochemical processes in detail. Nonetheless, few studies have been performed in South Korea. In this study, we compared two purification methods previously reported using an anion exchange resin (AG^ⓡ MP-1M), developed the best method in our lab environment, and then verified it by measuring Cu isotopic compositions in two USGS geological reference materials (BHVO-2 and BIR-1a). Although all matrix cations causing mass bias were effectively removed through both two methods with the yield of better than 95%, the method using the mixture of HCl and H₂O₂ only displays Cu isotopic compositions, in excellent agreement with reported values within the error. The method developed in this study is expected to be commonly applied to earth and environmental sciences.

구리 동위원소, 전이금속, 암석표준물질, Copper, Cu isotopes, MC-ICP-MS, geological reference materials

황정환 Jeonghwan Hwang , 정성욱 Sungwook Choung , 박찬수 Chan-soo Park , 한정희 Jeong-hee Han , 전소담 Sodam Jeon

DOI: Vol.29(No.4) 229-238, 2016

This study evaluated potential application of illite, which is produced at Yeongdong area in Korea, to remove radiocesium released to environmental system through severe nuclear accidents. The Yeongdong illite was formed by metamorphose of micaceous schist in hydrothermal condition, and composed of quartz, illite, and albite. Sorption distribution coefficient (K_d) of cesium by the Yeongdong illite was higher than the K_d values for other clay minerals. It may be affected by preferential adsorption of cesium to Frayed Edge Sites (FES) on illite. Nonlinear isotherm models were suitable to describe the sorption processes for the Yeongdong illite. Its max. single layer capacity was 250,000 μg kg^-1 for cesium. Therefore, the Yeongdong illite could be an efficient and economic sorbent to prevent dispersion of radiocesium, and apply for remediation.

방사성 세슘, 흡착, 영동 일라이트, 정화, radiocesium, adsorption, Yeongdong illite, remediation

우현동 Hyeon Dong Woo , 장윤득 Yun Deuk Jang

DOI: Vol.29(No.4) 239-254, 2016

The Hwangto cave is a sea cave which is located near shore in the Taeha-ri, Ulleung Island, being composed of the reddish tuff wall rock, the topic of this study, and the trachyte ceiling rock. The chemical compositions of the red tuff layer are 49.81-63.63% of SiO₂, 13.05-24.91% of Al₂O₃, 2.67-5.82% of Fe₂O₃, 2.87-6.92% of Na₂O, 2.37-3.85% of K₂O, 0.55-0.81% of TiO₂, 0-0.53% of MnO, 0.39-1.75% of MgO, and 0.60-1.40% of CaO with a pH ranging from 4.5 to 8. The reddish tuff are composed of 23.7-39.4% of anorthoclase, 16.9-33.3% of sanidine, 15.8-26.1% of illite, 5.1-9.0% of hematite, 0-3.7% of goethite, 6.9-9.9% of titanium oxide, and 0.9-9.5% of halite in mineral composition. Although it only includes anorthoclase, sanidine, and illite as major minerals, there can be additional vitric minerals that could not detected by the XRD. The mineralogy and textures of the tuff layer indicate that it became reddish due to the formation of amorphous palagonite and the oxidation of the iron as a heat from the trachytic lava affects the underlying tuff to altered. This iron oxides are enriched in the palagonite, or form microcrystalline or amorphous minerals. We thus suggest that the red tuff layer was generated by the combination of the thermal oxidation involved in the trachytic lava flow on the tuff layer, the palagonitization of the matrix of the tuff, and the oxidation of iron-bearing minerals.

적색 응회암층, 열적 산화작용, 팔라고나이트, Reddish tuff layer, Thermal oxidation, Palagonite